Filed by: ncsoregi [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=307392032&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/WO49IzwIS6CNqCshmYbbfQ/runs/0/artifacts/public/logs/live_backing.log
Reftest URL: https://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/WO49IzwIS6CNqCshmYbbfQ/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

[task 2020-06-24T15:36:58.323Z] 15:36:58 INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | dom.ipc.keepProcessesAlive.web should not be accessed more than 32 times. - 8 <= 32 -
[task 2020-06-24T15:36:58.324Z] 15:36:58 INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | memory.ghost_window_timeout_seconds should not be accessed more than 32 times. - 1 <= 32 -
[task 2020-06-24T15:36:58.327Z] 15:36:58 INFO - Buffered messages finished
[task 2020-06-24T15:36:58.328Z] 15:36:58 INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_preferences_usage.js | Should have accessed all known problematic prefs. Remaining: layout.css.dpi - Got 1, expected 0
[task 2020-06-24T15:36:58.328Z] 15:36:58 INFO - Stack trace:
[task 2020-06-24T15:36:58.329Z] 15:36:58 INFO - chrome://mochikit/content/browser-test.js:test_is:1327
[task 2020-06-24T15:36:58.329Z] 15:36:58 INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_preferences_usage.js:checkPrefGetters:81
[task 2020-06-24T15:36:58.330Z] 15:36:58 INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_preferences_usage.js:open_10_tabs:181
[task 2020-06-24T15:36:58.330Z] 15:36:58 INFO - Leaving test bound open_10_tabs
[task 2020-06-24T15:36:58.331Z] 15:36:58 INFO - Entering test bound navigate_around

Reopening this bug as a new intermittent and closing out Bug 1490990 as it's 2 years old.
First occurrence of this intermittent as mentioned here:
https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=f78c743cce37d5e4686ba679db26ad665743526a&selectedTaskRun=T3m6MfnJReC4crZW0oFqHg.0&searchStr=Linux%2C18.04%2Cx64%2Cdebug%2Ctest-linux1804-64%2Fdebug-test-verify-e10s%2C%28TV%29

https://wiki.mozilla.org/Bug_Triage#Intermittent_Test_Failure_Cleanup
For more information, please visit auto_nag documentation.

New failure instance: https://treeherder.mozilla.org/logviewer?job_id=368098611&repo=autoland

https://wiki.mozilla.org/Bug_Triage#Intermittent_Test_Failure_Cleanup
For more information, please visit auto_nag documentation.